Balloon coating with drug transfer control via coating thickness

Abstract

A coated medical device, such a balloon or stent. The coating includes a therapeutic agent having a thickness of the coating is between about 1.5 to 10 μm and less than 30% of the coating remains on the balloon post delivery to a vessel.

Description

FIELD OF THE INVENTION[0001]The present invention is related to the delivery of drugs from an insertable medical device. More particularly, the present invention relates to a coated balloon having a coating thickness exhibiting improved coating transfer efficiency and / or uptake of therapeutic agent to a blood vessel wall.BACKGROUND OF THE INVENTION[0002]Atherosclerosis is a syndrome affecting arterial blood vessels. It is a chronic inflammatory response in the walls of arteries, which is in large part due to the accumulation of lipid, macrophages, foam cells and the formation of plaque in the arterial wall. Atherosclerosis is commonly referred to as hardening of the arteries although the pathophysiology of the disease manifests itself with several different types lesions ranging from fibrotic to lipid laden to calcific. Angioplasty is a vascular interventional technique involving mechanically widening an obstructed blood vessel, typically caused by atherosclerosis.[0003]During angio...

AI Technical Summary

Benefits of technology

[0008]The present invention includes a drug delivery balloon which exhibits improved coating transfer efficiency to the wall of a blood vessel and / or increased uptake of therapeutic agent into a blood vessel wall. Generally, the balloon of the invention has a coating applied to at least a portion of the balloon surface. The coating has a thickness of about 1.5 to about 10 μm. Preferably, the coating has a thickness is of about 2 to about 6 μm. It has surprisingly been found that a drug delivery balloon having such a coating thicknesses exhibits greater coating transfer efficiency and therapeutic uptake.

Problems solved by technology

Although the blood vessel is often successfully widened by angioplasty, sometimes the treated wall of the blood vessel undergoes vasospasm, or abrubt closure after balloon inflation or dilatation, causing the blood vessel to collapse after the balloon is deflated or shortly thereafter.

It was then discovered that a drawback of drug eluting stents was a condition known as late stent thrombosis, which is an event in which blood clots inside the stent.

Stent thrombosis, whether acute or late, can be fatal in over one-third of cases.

Although drug eluting balloons are a viable alternative, and in some cases appear to have greater efficacy than drug eluting stents as suggested by the PEPCAD II study, drug eluting balloons present unique challenges.

Thus, there are challenges specific to drug delivery via a drug coated (or drug eluting) balloon because of the necessity of a short inflation time, and therefore time for drug or coating transfer—a challenge not presented by a drug eluting stent, which remains in the patient's vasculature once implanted.

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